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Bats Plagued by Mysterious 'White-Nose' Disease

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Bats Plagued by Mysterious 'White-Nose' Disease

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Bats Plagued by Mysterious 'White-Nose' Disease

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IRA FLATOW, host:

For the rest of the hour, we're going to take a look at a mysterious epidemic that is killing bats by the hundreds of thousands. Last year, a biologist in New York State reported finding thousands of bats dead, or soon-to-be-dead bats, that had an unusual, white, fuzzy coating around their noses. And that fuzz turned out to be a fungus.

And that's the only visible symptom of the disease which scientists have dubbed "white-nose syndrome." The illness hits bats that are hibernating in caves or mines and it causes them to lose weight. They emerge early. They are premature, right in the middle of the snow, presumably going out looking for food. And so far, hundreds of thousands have died, and scientists are scrambling to find out the cause.

The disease is not isolated to just New York State. It has spread to other parts of the Northeast, including Vermont, Connecticut, Massachusetts and possibly Pennsylvania. And if you'd like to visit one of those bat caves, we have a video for us. Flora Lichtman, our digital producer, went to upstate New York into a bat cave.

And you can take it towards the bat cave and see the bats, the dead and dying bats, and the scientists there taking samples, on our Web page, sciencefriday.com. Talking to me now - talking with me now to elucidate are my next guests. Elizabeth Buckles is a veterinary pathologist. She is also assistant professor of pathology at the College of Veterinary Medicine at Cornell. Thanks for being with us today.

Dr. ELIZABETH BUCKLES (Pathology, College of Veterinary Medicine, Cornell University): Hi, Ira. How are you doing?

FLATOW: You're welcome. Thomas Kunz is a professor of biology and director of the Center of Ecology and Conservation Biology at Boston University. And I want to thank you, Dr. Kunz, for taking time to visit with us today.

Dr. THOMAS KUNZ (Director, Center of Ecology and Conservation Biology, Boston University): Thank you, Ira.

FLATOW: How mysterious, Tom, is this?

Dr. KUNZ: Well, it is very mysterious. In my lifetime - I've been studying, doing research on bats for over 40 years, and I must say this is an unprecedented event. We really have never seen anything like it.

FLATOW: How was it discovered?

Dr. KUNZ: Well, basically, cavers and biologists who annually - or actually every two years, visit caves to do a census, and when they were visiting some of these winter hibernacula in New York State, they noticed this very unusual fungus on the nose. And in the year 2006, 2007, that winter, there weren't a lot of them.

There were only a few caves in which they saw a few bats that had this fungus, and it was an alarm, you know, was set off at that time, but really, there was nothing other than trying to survey other caves to see the extent of this. This year - and there were a number of - several thousand bats killed in that year. I think there were three caves that white-nose was discovered in, but you know, it was people - and I think Beth can probably address some of this.

There were samples that were sent off to different laboratories to try to identify the fungus, to try to identify whether they had certain pathogens or there were contaminants and so on, but nothing to date. Even in specimens that had been examined this year show any signs of this contamination or pathogenicity.

FLATOW: We're talking about the mysterious deaths of bats all over the Northeast this hour. Talk of the Nation Science Friday from NPR News. I'm Ira Flatow, with Elizabeth Buckles and Thomas Kunz. Beth, I was watching a video that we went into the bat cave. Flora went in there and it's just amazing. She was showing us that the bats have little white speckles on their skin.

Dr. BUCKLES: Right, right. That is the first sign that there's something wrong with the cave, and I want to emphasize that this is a syndrome and the fungus appears to be a sign of a sick bat or a sick cave, rather than, necessarily, the cause of death. So, it's just the most visible marker that something is going wrong in the hibernacula.

FLATOW: But the whiskers, tell us about why the whiskers are white.

Dr. BUCKLES: Well, what it seems to be is fungal colonies that are actually growing on the nose and on and around the skin of the nose. If you were to pick up one of these bats and spread its wings, you can also find similar colonies on the skin of the wings, the patagium and the tail skin.

FLATOW: And so, there are people now taking samples and trying to figure out where or what it is. As you say, it's a syndrome, we don't know what the agent is yet.

Dr. BUCKLES: Right, or if there is the agent. So, you know, it's - when we were contacted by the New York Department of Environmental Conservation, the veterinary school initiated a disease-outbreak investigation. And because we were dealing with dead animals, what we did is we began with growth necropsy examinations.

And looking at the histology, the microscopic examination of their tissues, we also submitted tissues to numerous labs including our own animal health and diagnostic lab, to survey for viruses, fungi, and bacteria. To date, we have no consistent findings.

We can culture fungus from the skin of bats, but when I look at that underneath the microscope, there doesn't seem to be any reaction to the fungus that is on their skin. So, the bats aren't responding to it and it's very superficial. We also don't see any damage to the internal organs because of the fungus or any other pathogens.

FLATOW: So, what it looks like - from seeing the video, it looks like the bats wake up in the middle of the hibernation season...

Dr. KUNTZ: Well, Ira...

FLATOW: They fly out, and they die of hunger.

Dr. KUNZ: Yes. I mean, one of the clearer conditions of these bats, as you pointed out early on, is that they basically have used up most of their fat by midwinter. Normally, they'll have fat reserves that sustain them through the winter. It makes it possible for them to arouse and go out and to start feeding.

And this is usually by mid- to late April is when they - they're starting to emerge now, on warmer days or warmer evenings. But the curious thing is that the fat is basically depleted by midwinter, and in fact, some of the bats cannot arouse. And there are actually two different kinds of fat that hibernators have, and that they have what is called brown fat and white fat.

The brown fat is just a little pad of a very highly-vascularized, with a large number of mitochondria in it, which is basically like a little furnace. And this makes it possible for bats to undergo the first stage of arousal. The bat's a hibernator, the first stage of arousal, what is known as non-shivering thermogenesis.

It's a metabolic heat, basically, produced by the metabolism that goes on in this little brown fat. The fuel is the white fat that we, all of us have, but this fuel has been depleted, and also the furnace seems to be also - that is, the brown fat, seems to be depleted...

FLATOW: Right. Tom, I'm going to have to interrupt a little. We'll talk more about the bat physiology with this, right after the short break. Stay with us. We'll be right back.

(Soundbite of music)

FLATOW: I'm Ira Flatow. This is Talk of the Nation Science Friday from NPR News.

(Soundbite of music)

FLATOW: You're listening to Talk of the Nation Science Friday. I'm Ira Flatow. A brief program note. This Wednesday, Neal Conan broadcasts live from the Newseum in Washington. And if you're going to be in Washington and you want a special event to go to, you can join the live audience there with Neal and all the gang in the Newseum.

But if you want tickets, this is what you have to do. Get your pencil out. You have to send an e-mail to talk - that's talk@npr.org, and in the subject line, put "tickets." Don't put lunch or anything else. You want "tickets," for talk@npr.org and that'll get you - hopefully there's tickets, there's room left, to get tickets there.

We're talking this hour about the bats that were mysterious die off in upstate New York, and parts of New England, now spreading around, maybe even into Pennsylvania. Hundreds of thousands of bats dying of a mysterious syndrome that's killing them. They're losing weight and we - Flora Lichtman went into one of these bat caves in upstate New York and here's what...

(Soundbite of bats)

FLATOW: That's the sound of a little brown bat.

(Soundbite of bats)

FLATOW: And we have video of that trip that Flora went in there and you can see the cave, and the scientists are trying to figure out what's killing off these bats, on our Web site, on sciencefriday.com.

Here with me to talk about what the possibilities are and to talk more about the disease are, back with us, are my guests, Elizabeth Buckles, a veterinary pathologist, and Thomas Kunz, a professor of biology at Boston University. Tom, you were - when I interrupted you, you were talking to us about how the bats were starving slowly to death by the loss of the fat that they normally would have.

Dr. KUNZ: Yes, Ira. What it turns out is that many of the bats that are afflicted by white-nose syndrome, either - some are able to arouse and they do go out and fly around, as you pointed out in midwinter. There's snow on the ground and so on.

But many of them simply don't arouse at all and die right in the caves, and that's the part of the reason why we're concerned that, you know, that they've lost the body fat, they've - and why they are metabolizing or losing so much fat over the winter. There are the other hypotheses about why they run out of fat in midwinter, and one of them is they may not have put on enough fat in the fall. Typically, they put on fat in September and early October and then enter hibernation.

It's very possible that, for reasons that we don't know, that maybe insect populations happened to be low due to the spraying of pesticides. They may have eaten insects that were sprayed with pesticides. That may have affected their ability to deposit fat. They're just - there're a number of just unknowns at this point.

FLATOW: So, if people are going out now, the weather is getting better. They may be finding sick or dead and dying bats littering all over the cave spaces.

Dr. BUCKLES: That and on the landscape, and what we caution is, whenever you approach any wild animal, you should do so with extreme caution. If the public does encounter a bat that they believe is sick or injured or may be affected by this, what we're recommending is they contact, at least in New York, the Regional Department of Environmental Conservation Office or the Department of Health.

FLATOW: Mm hm. 1-800-989-8255. Let's go to the phone, Alex in Dearborn. Hi, Alex.

ALEX (Caller): Hi, Ira, I'm glad to be on the air. I have a question. Last year, I heard about the bees that were abandoning their hives...

FLATOW: Right.

ALEX: And I know that bats consume large quantities of insects. And I just wondered if there was any kind of cross-correlation between insect populations crashing or abandoning their normal habitats, and if this could be affecting the bats, because they are kind of the top of the food chain.

FLATOW: Good question, yeah. Good question.

Dr. KUNZ: Well, it's a good question and one we don't have a good answer to. I think I could you know, simply point out that, you know, first of all, bats don't eat bees, but as you suggest, that whatever is affecting the bees or something similar to that may be affecting other insect populations. And there is simply not enough insects to go around at that time of year when they're depositing fat, they may not be putting on sufficient amounts of fat. There is always a threshold of when the insects, whatever they happen to be, there may be a threshold level that will not sustain these bats.

Dr. BUCKLES: The one thing that bees and bats do have in common, they are animals that have very different physiology, obviously. But the reason bees get a lot of press and people notice is because these are animals that congregate in large numbers. So, if something happens to affect them, large numbers of them are affected, and we get these spectacular die-offs. So it is concerning that we have die-offs in animals that tend to roost together, but as far as a direct correlation, that would be something that would be purely speculative.

FLATOW: Tom, if all of these hundreds of thousands of bats, and who knows, could be more that we haven't discovered yet are dying, don't bats eat a lot of mosquitoes and things like that?

Dr. KUNZ: Well, it turns out that bats don't eat as many mosquitoes as sometimes people say they do. They do eat lots of insects, and many of the insects they do eat are pests, particularly pests of gardens, garden crops, and agricultural crops, and forest trees, and so on. So they do play a very important role in suppressing insect populations. In terms of actually having their impact on mosquitoes is probably overblown.

FLATOW: But there is a niche in the ecosystem that they occupy.

Dr. KUNZ: Absolutely. These are all bats that feed on insects, and they, you know, they forage long distances away from where they roost. They can fly, you know, several kilometers a night in feeding. They eat up to their body weight a night in insects, when, if there are enough insects there. So it's a very important role that they do play.

FLATOW: We have a question from Tammy(ph), on Second Life. And she says, is it possible they're being preyed upon less. And hence, they are over populated and being stressed more of that, who eats bats is what...

Dr. KUNZ: I would say they are not over populated. In fact, over the years, bat populations have declined worldwide. They have been declining in New York State. They have been declining, in fact, throughout the rate most species have. Not only bats that roost in and hibernate in caves, and roost in buildings and so on, but also, ones that roost in trees, and are migratory species. They have actually been - there are high mortalities that are occurring. In fact, interestingly - the previous - when you're previous part of the program, when you were talking about renewable energy and so on, wind energy is one of those forms of renewable energy. And it turns out that wind turbines are killing large numbers of bats that previously have never been killed before like that. So, you know, they were sort of getting hit, the tree-dwelling bats are getting hit by the wind turbines and whatever white nose is, is also affecting those. I would say, there is not an over population of bats anywhere.

FLATOW: 1-800-989-8255. Our listeners are trying to scratch their heads and think about them. What, could it be themselves? John in Ellerbe in North Carolina, right?

JOHN (Caller): Right. My question is, have you done some investigation into their immune system? I know, it's hard to isolate the viruses that seem to cause HIV. Could it be that if you look into their T-cells and whatnot, you could find some explanation for this disease?

Dr. BUCKLES: Those are on-going studies, and I think some people that Tom works with, up in Boston have been doing those studies. So they have some good baseline data. But that is a question that we are asking ourselves, if there could be an immuno-suppressant virus or other immunosuppressive affects. Even if you had an immuno-suppressive agent, you know, people who have HIV or immuno-suppression, don't die of HIV. They die of all the concomitant infections, opportunistic infections that inhabit their body. So, although the immune system is very important and it's something we need to investigate, we're not seeing an overwhelming infection in these bats with an opportunistic bacteria, or virus, or fungus.

FLATOW: Could there be some environmental factor from something man-made, some kind of pollution, or lead, or something, mercury, something like that?

Dr. BUCKLES: Yes, the toxicology studies are also ongoing. Unfortunately, toxicology is very complex. It's not like on television where you just submit a piece of tissue and say, run toxicology.

FLATOW: Oh! No!

Dr. BUCKLES: Oh! It's not. So, you have to ask for a certain test. So, we've done basically the first initial line of testing for common pesticides, lead, and other heavy metals. That has not turned up anything but now we have to look in to some other pesticides that aren't as common, some other chemicals in the environment or could the chemical in the environment be having a secondary effect on the bats by killing insects? So, there may not be a straight line to this answer.

FLATOW: Well, the reason I asked is because all that wind keeps blowing in the Northeast you know, from everywhere else. It winds up there with all the schmutz in it and that comes from all the power plants and things up wind.

Dr. KUNZ: That's right.

FLATOW: And you know, we've had insects right, the insects with high levels of heavy metals in them dying. And you've had - you know, it first started out with acidified lakes and things like that.

Dr. KUNZ: There examples in recent years of declines of moth populations are not just here in the Northeast, in other parts of the world. So, I think we have to really take a very close look at - not only what is possibly causing the declines of these insect populations, but again, if there's a link to the decline in the insect populations and white nose. That's something we're all scrambling with various kinds of hypothesis. A group has been formed, a group of scientists from several different laboratories across the U.S. We're going to be meeting in June to try to put our heads together to try to figure out where we go next with this. But clearly it's a problem that we're going to have to try to face, and you know, many of us here are putting our heads together to do that.

FLATOW: If you do find out that there is vector like a virus or a bacteria, something like that. Is there anything you could do about you know, giving medicine, so to speak, or antibiotics, whatever we might need, to the bats? Can you give them, you know?

Dr. KUNZ: Well, I don't think that's a practical solution. You know, this has been, people have discussed this with regard the rabies. Can we immunize all wild animals? And certainly it's been done to some extent with wolves and canids in certain parts of the world. But it would be very impractical to try to immunize bats in their caves or other roosts. I mean you raised a very good question. What do we do if we identified something, whether it's a virus or whether it's a bacterium, or whether it's a contaminant or so on? All we can do is raise the issue that if it is something like a contaminant, then it's a little bit more easily solved. When it is say a pathogen of some sort, it may take its toll on the population. As in most organisms, you know, there's a certain distribution of different kinds of characteristics that organisms have. There's a variation, and there's going to be some that will survive.

Dr. BUCKLES: And what we would do is we had talked to the management expert the Fish and Wild Life Service, Department of Environmental Conservation, the agencies in the different states. And talk to them about what we do to optimize either the survival of these animals through the winter. Are there ways we can relieve certain stresses that we'd have to identify or are there ways we can optimize the potential for the survivors to breed during the summer? So if they do, if we do get a group of survivors, how can we help them best repopulate?

FLATOW: Talking about the bat die-off going on here in the Northeast on Talk of the Nation Science Friday from NPR News. I imagine that the bell has gone out and people around the country, if not the world, are also looking for signs of these. Would I be correct in assuming that?

Dr. KUNZ: Well, there are people looking in other states. Certainly, and these bats that live here in the Northeast, also you know, live out in the Midwest and extend out into the western states and into the southern states, and so, it is a concern that if in fact it does spread, whatever it may be, we are going to have to really take a very careful look.

FLATOW: But if it doesn't spread, wouldn't that tell you something also?

Dr. KUNZ: It definitely would.

Dr. BUCKLES: It definitely would.

Dr. KUNZ: It would tell us something about there is something here in this region that may be causing this. Now, one of the very curious things, many of the sites where white nose has been found are mines, that is, they are old abandoned mines. There are a few caves in which white nose has been found, but most of them are mines, and you know, whether there is something affiliated, associated with conditions in the mines, there is one very curious observation that has been made, and that is that the sites where white nose has been found are largely those which have very high humidity, obviously cold, as the temperatures are in these caves, but the sites that do not have any evidence of at least the external manifestation like the white nose, are in very dry caves and mines. So, there may be some link to water, there may be some link to the water - you know, the atmospheric conditions in you know, in moist environment versus a dry environment. These are all things that we just simply are trying to grope with.

FLATOW: With the new outbreak of something not seen before, do you have new funding to take care of? You know, with doing all this research?

Dr. BUCKLES: New funding? That is always one of those things we have to talk about in strategic meetings is how to find funding to do these things. Most states and some federal agencies do have a limited amount of funding to do disease research in wildlife for outbreak investigations, but what we are looking at here is finding funding for some fairly long-term studies, and that is one thing we're going to have to talk about.

FLATOW: And states these days don't have a lot of money to throw around.

Dr. BUCKLES: Yes. The economy is not in a position right now where we think we're going to be particularly flushed with money to do a lot of things.

FLATOW: Maybe the Gates Foundation is listening.

Dr. KUNZ: We are exploring various options. Certainly, private foundations, the federal government, as we know, the federal government moves very slowly on these things. I mean, there are funding sources either through the potential sources, through the National Science Foundation and National Institutes of Health that we can explore. But often times, those, it takes time to get those proposals together and get them reviewed and so on, but you know, what we're really looking for in the short run here are funds that can make it possible to really mobilize.

Dr. BUCKLES: Yes, something we could, to rattle it...

FLATOW: Are you looking for individual donations then?

Dr. KUNZ: Absolutely. The individual donations, foundation donations...

FLATOW: If people want to donate, how should they contact this project?

Dr. KUNZ: Well, Bat Conservation International, based in Austin, Texas is one that is helping coordinate some of the research going on, and you know, they are a private foundation that is well-linked to this particular effort and certainly, the universities are involved. There are a number of them and other state institutions, but I think it is best probably, funnel it toward Bat Conservation International.

Dr. BUCKLES: And you can certainly, again through our universities, you know contacting either Boston College or the College of Veterinary Medicine. We could certainly help people who wanted to find a way to help with this issue.

FLATOW: OK. Good mystery around it. Thank you, and don't pick up those bats. You see them lying them around in the caves.

Dr. BUCKLES: But call someone if you see them.

FLATOW: Yeah, yeah. Thank you, Elizabeth. Elizabeth Buckles is Veterinary Pathologist and an Assistant Professor of Pathology at the College of Veterinary Medicine at Cornell. Thomas Kunz is Professor of Biology and Director of the Center for Ecology and Conservation at Boston University. Good luck to you.

Dr. KUNZ: Thank you, Ira.

Dr. BUCKLES: Thank you, Ira.

FLATOW: We'll stay in touch.

Dr. KUNZ: Okay, thanks. Bye.

FLATOW: You're welcome. Greg Smith, composed our theme music, and we had help today from NPR Librarian, Kim Moleski(ph). If you want to know more about the bat - if you want to see the bat video? Surf over to our website. It's sciencefriday.com. We've got a really good video up there showing you the bats in the caves and the die-off that's going on and the research and links how to reach the bat people if you are interested.

Also, in Second Life, you can talk to some other avatars and discuss the issues and talk to us and they were broadcasting and blogging and looking for your videos. Please send us your videos. We'd like to feature them. Anything having to do with science, technology, medicine, and the environment, you know. We'll take a look at them and try to feature them on our website. Have a great weekend. Have a Happy Passover. I'm Ira Flatow in New York.

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